The present invention relates generally to a transdermal delivery system which is applied onto the skin or mucosa of a host, for systemic delivery of a therapeutic agent. More particularly, the invention is directed to a titratable dosage transdermal delivery system that comprises a plurality of patch units connected along one or more borders. The plurality of patch units are divisible into respective units along the one or more borders having one or more lines of separation. The dosage provided by the transdermal delivery system is proportional to the number of units applied by the user as determined by a physician. Each patch unit comprises at least a backing layer and a drug layer formulated with at least one therapeutic agent. The transdermal delivery system enables administration of a titratable dosage of therapeutic agent on a solid support to the skin or mucosa of a host. Furthermore, the invention is directed to a method of making the transdermal delivery system. Still further, the invention is directed to a method of providing a titratable amount of therapeutic agent to a host using the transdermal delivery system of the invention.
One approach to sustained delivery of a therapeutic agent is the use of transdermal delivery system such as transdermal patches. Generally, transdermal patches contain a therapeutic agent and an adhesive which allows the transdermal device to adhere to the skin of a patient, allowing for the passage of the active agent from the device through the skin of the patient. Various advantages of using transdermal patches include constant rate of delivery of therapeutic agent, longer duration of action (the ability of the patch to adhere to the skin for 1, 3, 7 days or longer), non-invasive application, improved patient compliance, and the supply of therapeutic agent may be interrupted at any time by tearing off the system. The importance of this means of administration resides in the fact that therapeutic agent can be delivered to the bloodstream without traversing the gastro-intestinal tract and avoiding a xe2x80x9cfirst passxe2x80x9d through the hepatic system prior to reaching the target site. This would avoid any gastrointestinal incompatibility with the pharmaceuticals and unwanted destruction of the pharmaceuticals by metabolism in the gastrointestinal tract. Once the therapeutic agent has penetrated the skin layer, it is absorbed into the blood stream where it can exert a desired pharmacotherapeutic effect. These benefits may be obtained without requiring a professional to administer the therapeutic agent. Transdermal absorption minimizes inter- and intra-patient variations regarding such incompatibilities and metabolisms. By transdermal absorption, it is deemed possible to provide more constant pharmaceutical concentration in the body and to realize a greater pharmaceutical efficiency. It is possible, by proper transdermal absorption, to provide effective dosing of therapeutic agent.
Current pharmaceutical practice provides for transdermal system or transdermal patch that delivers therapeutics at fixed dosages. The rate of delivery of therapeutic agent from the patch to the skin or mucosa of a host, known as the flux rate, is constant and predetermined by the individual patch that is prescribed. The economics of manufacturing and government approval limit the availability of patches with different dosages. Presently, a pharmacist needs to stock multiple patches each containing various dosages of therapeutic agents. For example, a pharmacist needs to stock five different types of transdermal patch, each having dosage strengths such as 25, 50, 75, 100, 150 units per time (micrograms/hour). When a doctor prescribed a certain patch having a certain dosage strength to a patient, the patient purchases enough supply of transdermal patches having the fixed dosage of therapeutic agent. If the prescribed amount is too strong, the patient will have to purchase another supply of transdermal patches having a reduced dosage of therapeutic agent. If the prescribed amount is too weak, the patient will have to purchase another supply of transdermal patches having an increased dosage of therapeutic agent. In this current practice, patches that do not provide the optimum dosage for the patient are being wasted.
Thus, there remains a long felt, yet currently unmet need to provide a transdermal delivery system that can deliver titratable dosage of therapeutic agent. This titratable dosage transdermal delivery system has the advantage of minimizing wastage of transdermal patches that do not provide optimal dosage level of therapeutic agent. There is also a need for a transdermal system which allows fine control of dosage of therapeutic agent to be delivered to a patent. The transdermal delivery system of the present invention solves the problem by providing adjustable dosage of therapeutic agent from a single transdermal delivery system. This invention reduces the number of different types of transdermal patch having various dosage strengths that need to be stocked by a pharmacist. For example, the pharmacist mentioned above would only need to stock two types of transdermal delivery system of the present invention. One type has a dosage of 25 units per patch and the second type has a dosage of 75 units per patch unit. From these two types of patches, it is possible to deliver various dosage strengths such as 25, 50, 75, 100, 150 units. For example, in order to achieve a strength of 50 units, 2 patches of the 25 unit dosage per patch unit may be used. To achieve a strength of 100 units, 4 patches of the same type of patch may be used. To achieve a strength of 150 units, 2 patches of the 75 unit dosage per patch unit may be used. Instead of stocking five different kinds of patches containing different dosages, only two different kinds of patches need to be stocked.
The present invention is based upon the observation of the inventor that an optimal dosage of therapeutic agent may be delivered to the skin or mucosa of a host, by means of a titratable dosage transdermal delivery system. The present system addresses three shortcomings of the current technology. First, with the advent of transdermal patch, self-administration by a patient is generally involved. Patient compliance with application instructions takes on great importance. The present system provides an easy method of adjusting the dosage of therapeutic agent by the patient through the use of the system of the invention by following simple instructions from the physician. Second, the present system reduces the number of therapeutic patches with different dosages that need to be stocked by a pharmacist. Third, the present system reduces wastage of transdermal patches that have suboptimal dosage of therapeutic agent.
It is an object of this invention to provide a titratable dosage transdermal delivery system for the systemic delivery of one or more therapeutic agents to the skin or mucosa of a host.
The system comprises a plurality of patch units connected along one or more borders. Each patch unit comprises: a backing layer having a top surface and a bottom surface; a drug layer disposed on the top surface of the backing layer; and a means for adhering the patch unit onto the skin or mucosa of a host layer, where each patch unit is defined by one or more lines of separation on the border.
In one embodiment, the system comprises a plurality of patch units connected along one or more borders. Each patch unit comprises: (a) a backing layer having a top surface and a bottom surface; (b) a drug layer with matrix layer disposed on the top surface of the backing layer; and (c) an adhesive layer disposed on the drug layer with matrix layer, wherein each patch unit is defined by one or more lines of separation on the border.
In one embodiment, the system comprises a plurality of patch units connected along one or more borders. Each patch unit comprises: (a) a backing layer having a top surface and a bottom surface; (b) a drug layer with matrix layer disposed on the top surface of the backing layer; (c) an adhesive layer disposed on the drug layer with matrix layer; and (d) a cover layer disposed on the adhesive layer, wherein each patch unit is defined by one or more lines of separation on the border.
In another embodiment, the transdermal delivery system comprises a plurality of patch units connected along one or more borders. Each patch unit comprises: a backing layer having a top surface and a bottom surface; a drug and adhesive layer disposed on the top surface of the backing layer; and a cover layer disposed on the adhesive layer, wherein each patch unit is defined by one or more lines of separation on the border.
Moreover, it is an object of the present invention to provide a transdermal delivery system which comprises a plurality of patch units connected along one or more borders. Each patch unit comprises: a backing layer having a top surface and a bottom surface; a drug and adhesive layer disposed on the top surface of the backing layer; a release limiting layer disposed on the drug and adhesive layer; a second drug and adhesive layer disposed on the release limiting layer; and a cover layer disposed on the release limiting layer, wherein each patch unit is defined by one or more lines of separation on the border.
In addition, it is an object of the present invention to provide a method of making the transdermal delivery system which delivers a titratable dosage of drugs to a patient. The method comprises forming a backing layer with top and bottom surfaces, which backing layer is divided into more than one unit at one or more lines of separation. A drug-in-matrix layer is disposed on the top surface of each unit of the backing layer, leaving a border on all sides of the backing layer. An adhesive layer is disposed on the drug-in-matrix layer and the border of the backing layer. A cover layer is then disposed on top of the adhesive layer.
Still further, in one embodiment, the method comprises forming a plurality of reservoir compartments within an enclosure defined by the raised wall directly on a backing layer. Each reservoir compartment is surrounded by a border having a surface. One or more lines of separation are formed on the border dividing the plurality of the reservoir compartments into separate units. A drug layer is disposed into each of the reservoir compartments. An adhesive layer is then disposed on top of the drug layer and on the surface of the border. A cover layer is then disposed on the adhesive layer which covers the surface of the border and the adhesive layer.
Furthermore, it is an object of the present invention to provide a method of making the transdermal delivery system which delivers a titratable dosage of drugs to a patient. The method comprises forming a backing layer with top and bottom surfaces, which backing layer is divided into more than one units at one or more lines of separation. A drug-in-adhesive layer is disposed on the top surface of each unit of the backing layer, leaving a border on all sides of the backing layer. A cover layer is disposed on top of the adhesive layer.
Moreover, in one embodiment, the method comprises the steps of forming a backing layer with top and bottom surfaces, which backing layer is divided into more than one units at one or more lines of separation. A drug-in-adhesive layer is disposed on the top surface of each unit of the backing layer, leaving a border on all sides of the backing layer. A semi-permeable membrane is disposed on the backing film so as to hold the drug-in-adhesive within the border. A second drug-in-adhesive layer is disposed on the semi-permeable membrane. The border is covered with an adhesive. A cover layer is disposed on the drug-in-adhesive layer.
Finally, it is an object of the present invention to provide a method of delivering a therapeutic agent through the skin or mucosa of a patient. The method comprises providing a transdermal delivery system; separating a prescribed number of units of patches from the transdermal delivery system along at least one line of separation; and removing the cover layer exposing the adhesive layer and applying it on the skin or mucosa.